Circuit continuity check splice



Sem. E69 w58 H. B. WHITE zg CIRCUIT CCNTINUITY CHECK sPLICE Filed Feb. 2'?. 1957 IBA w/qlgglllllnylllllqg,

` l INVENToR. 'H 1w HARRY ENJHHE United States Patent CIRCUIT CONTINUITY CHECK SPLICE Harry B. White, Canton, Ohio, assignor to AMP Incorporated, Harrisburg, Pa.

Application February 27, 1957, Serial No. 642,716

' 8 Claims. (Ci. 200-51.11)

The technique of joining electrical wires has been considerably improved by use of the crimped electrical connector. This connector comprises a metal ferrule adapted to be cold forged onto the wire. Securing a wire to each end of the ferrule by means of a crimped connection achieves an excellent electrical connection,

A further improved :form of the crimped type of electrical connection is disclosed in the patent to Watts, Patent No. 2,410,321. This patent teaches the improvement of providing an insulating sleeve over the outer surface of the connector to prevent the intrusion of moisture as well as prohibit the escape of electrical current from the circuit.

One difficulty in employing such a connection arises in the testing of the connection to ascertain whether or not a good electrically conductive joint has been formed. In a fairly vrcomplex circuit, several thousand (or more) of these crimped connections may be used. If a break occurs in the circuit, it is necessary to test each one of these conductive jo-ints to determine Whether or not it is carrying electricity.

It is an object of the present invention to provide an electrical connector which is sealed against the entrance of moisture, as well as the escape of electricity, wherein a means is provided for easily testing the electrically con-V ductive jo-int without destroying it. This testingimeans is built into the connector without sacricing any of the insulating properties described above.

It is also an object of this invention to provide an insulated electrical connection wherein the insulating sleeve is flexible so as to permit the contact in the circuit testing means to be operated between an open position and a closed position. Also the device incorporates a means for preventing over-flexure of the insulating sleeve, which may tend to destroy or weaken it, and a means for preventing inadvertent operation of the circuit testing assembly.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

Figure 1 is a perspective view of an electrical connector embodying principles of this invention;

Figure 2 is a plan View taken along cross sectional plane II-II of Figure 5 showing the device of Figure 1;

Figure 3 is a view similar to Figure 2 showing the electrical connector crimped onto a pair of electrical conductors;

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Figure 4 is the identical connector of Figure 3, shown in its electrical conducting position;

Figure 5 is a plan view of a cross section taken through lines V--V on Figure 2; and

Figures 6 and 7 are modied forms of connectors embodying principles of this invention.

One embodiment of a connector incorporating principles of this invention is of the type known as a butt connector, as set :forth in the patent to Broske, No. 2,478,082, issued August 2, 1949.

Referring now to the drawing, Figure 2 shows a pair of coaxial metal ferrules, 30, 32 secured together by a metallic strap 34. This assembly may be stamped out of a metallic sheet and rolled up so that the ferrules and the connecting strap are all integral. These t'errules are preferably made of copper, but may be made of any other material having good electrical conductive properties.

A seamless ferrule 36, 38 may be placed over each of the ferrules 30, 32 to prevent them from splitting open when crimping pressure is applied. Surrounding the entire assembly is a sleeve 33 of clear plastic insulation. This insulation is of the type capable of accepting crimping die pressure without shearing, rupturing or tearing. Preferably this plastic is transparent to permit visual inspection of the crimped connection.

The circuit continuity testing assembly comprises a metal stud or post 46 projecting from strap 34. A metal Contact member 42 is embedded in the surface of the insulating sleeve. As shown in Figures 2 through 5, the contact member 42 comprises a metal button which extends into the inner surface of the connector. The member 42 which extends into the inner surface of the connector is forced into snug engagement with the insulation sleeve and forms a waterproof seal therewith.

Insulated wires 5t), 52 having uninsulated end portions S4, S6 are inserted within metal ferrnles 312i, 32 respectively. As shown in the drawing, the inner edges of the wires S4, 56 project through the ferrules 30, 32 wherein they may be observed by the operator to assure proper positioning of the wires within the ferrules. The insulation on the wires is received by the outer metal -ferrules 36, 33 as well as the overlapping ends of the insulating plastic sleeve. In this position a plurality of crimps are impressed along the longitudinal surface of the insulating sleeve to join the outer ends of the sleeve to the insulation on the wire and the intermediate section of the connector to the conductor itself. This provides a mechanically secure, insulated, electrically conductive joint.

In this position the button 42 is disposed in spaced relationship from the stud 40 as illustrated in Figure 3. Electricity iiowing through conductor 54 is conveyed through metal ferrule 3), metal strap 34, metal ferrule 32, and into conducto-r 56. When it is desired to test the joint to ascertain whether or not it is carrying an electrical current, the button 42 is depressed until it comes into contact with stud 40. The flexible quality of the insulation permits movement of the button contact in this manner. A probe, designated by the letter T, or any other testing instrument may be applied to the contact 42 to take a reading of the electrical characteristics of the circuit. Y

The stud 40, in addition to furnishing a means for testing the conductivity of the joint, also functions as a means for resisting over-flexure of the insulation sleeve. Since the button 42 may only be depressed the width of the air space between it and the post 4t), the degree of ilexure required by the plastic is slight. The stud 4@ prevents the insulation from being flexed an amount greater than the original distance between the contact 42 and the stud 40.

It is also noted that the insulating sleeve 33 is recessed slightly along its intermediate section, i. e., between the ferrules. This accommodates the contact button 42' while minimizing the diameter of the assembly in this area. Furthermore, this protects the button Contact from accidentally touch-ing a grounding means. However, even if this should happen, the member 42 will not make contact with the studv 4t? unless, thepinsulating sleeve 33 is depressed. The sleeve 33 is sufficiently rigid to require the application of positive pressure to depress the button 42, which operates as` another safeguard against accidental grounding of the circuit.

The embodiment depicted in Figure 6. is similar to the embodiment shown in Figures 1- through 5 except that a further precaution against accidental grounding resides in the provision of a slidable insulation. sleeve Si', which insulates the contact 42'". An opening 53" in sleeve 51 is located near the button 42. When it is desired to test the circuit, the sleeve may be either moved longitudinally or else rotated to align the opening 53 and the button 42 thus exposing the contact 4Z. After testing, the sleeve 5l may be returned to its insulating position. The sleeve 50' may be knurled at either or both ends to prevent accidental displacement.

Figure 6 also illustrates how the stud 4t) may be omitted and the strap 34 deformed in such a manner as to perform the same function as the stud. In this form the strap is bent into the shape of an inverted U 40 with the bight of the U being disposed the desired distance from the button contact.

Figure 7 shows an embodiment of the invention, also similar to Figures 1 through 5, except that a reducedy central portion 60 isprovided so that the distance between button 42 and the central portion 60 provides the necessary air space to permit the assembly to function as a testing device.

The embodiments shown inFigures 6 and 7 operate in the same manner as the embodiment shown in Figures 1 to 4. Elements in Figure 6, corresponding to elements in Figures l through 5 are designated by prime numbers. In Figure 7 double prime numbers are used.

Thus it is seen that applicant has provided a strong, secure, crimped connection which may be easily tested for conductivity without destroyingV the insulation and moisture proof properties.

Changes in construction will occur to those skilled in the art and various apparently different modications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is oifered by way of illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. An insulated electrical connection joining a plurality 4 of conductors and including a pair of coaxial metal ferrules joined by a metal strap, a metal stud extending from the strap, a flexible plastic sheath surrounding the entire assembly, and a metal contact member extending through the sheath in the vicinity of the metal stud, whereby the plastic sheath may be deformed to permit the metal contact member to engage the stud.

2. The device of claim l wherein the plastic sheath has a reduced external diameter in the vicinity of the strap.

3. An insulated electrical connector including a pair of coaxial metal ferrules joined by a metalf strap, a ilexible insulating sleeve tightlly covering the ferrules and overlapping the outer ends of the ferrules, a metal member embedded in the plastic sleeve with one metal surface exposed to the interior of the sleeve and the opposite metal surface exposed to the interior of the sleeve, and said metal member being movable into or out of electrical engagement with the metal strap to permit' testing the electricall continuity of the circuit.

4. The device of claim l including a second insulating sleevesurrounding the metal member, said insulating sleeves being relatively movable.

5. Trhe device of claim 4' including an opening in the second" insulating sleeve, said opening being aligned with the-metal member in one relative position ofthe sleeves.

6. The` device ofA claim 3 wherein the metal strap is U-shaped;

7. An electrical connector including a pair of longitudinally coaxial metal ferrules joined by a metal strap, a flexible insulation sleeve tightly covering the ferrules, a metal member'embedded in the sleeve between the ferrules-andopposed to the metal strap, a metallic projectionon the strap extending toward the metal member, and

saidmetal being normally spaced from the projection but movablev by flexure of the insulation sleeve into contact.

electrical contactmember embedded in the plastic sleevey in the vicinity ofthe electrically conductive rnemberand spaced therefrom'projecting from the ferrule, whereby flexure of the insulatingsleeve permits contact' between the contact member and the electrically conductive member.`

References Cited'in the file of this patent UNITED STATES PATENTS 2,025,564 Blake Dec. 24, 1935 2,605,314.v Schelke' July 29, 1952 UNH@ STATES PATENT @FFME CERWNCATE @F @@RREC'HN Patent Noo 298523631 September' 16, 1958 e Harry Bo White It is herebr certified that error appears in theprnted specification of the above 'numbered patent requiring correction and. that the said Letters Patent should :fread as corrected below.

Column t? line 1,7, claim 3 for the Word "interior" read mexterior e e Signed and sealed this 16th day of December' l958 (SEAL) Attest:

KARL EL, A`X2l ,l,\`t`v ROBERT C. WATSON Atesting fcer Commissioner of Patents UNITED STATES PATENT OFFICE @E 'HNCATE @E COECTIUN Patent NoD 258529631 September 16, 41958 e Harry 1Bo White It is hereby certified that error appears in the-printed specification of the above V`murnbelced patent requiring correction and that the said Letters Patent should read as corrected below.

Column +7 line 1'7 9 claim 3y for the word "interior" read w exterior' e Signed and sealed this 16th day of Deeembelq 1958.,

(SEAL) Attest:

KARL AXLINEr ROBERT C. WATSON Attesting Officer Commissioner of Patents 

